The word "often", meaning the same as "often", "often", causes many difficulties in the placement of punctuation marks. Are commas required before and after the “often”? What does it depend on and what rules do you need to know in order to prevent a mistake?
The rule
The difficulty arises from the fact that “often” at first glance is easily mistaken for an introductory word. However, their main difference is the lack of grammatical connection with other members of the sentence. That is, it can be removed from the sentence. An introductory word cannot be asked.
“Often” answers the questions “when?”, “How often?” and in a sentence it is usually a circumstance of time. It is part of the subordinate phrases such as "adjacency" as an unchanging dependent word.
Thus, “often” is an adverb. It does not require isolation, unless there are other grounds for the punctuation marks. For example, a “often” is preceded by a comma if it is at the beginning of the participle or participle turnover.
Examples
"He often did not understand me and did not listen to my opinion." Punctuation marks are not required here.
"The chief of plans was not considered necessary in advance, often acting spontaneously and unpredictably." The sentence uses the participial turnover, so a comma is needed.
"Often, being an intelligent and pragmatic person, my friend did not participate in conversations about love." In this case, the commas are due to the presence of the sacramental participle - "being a rational and pragmatic person." The circumstance "often" as a secondary member of the sentence refers to the predicate "did not participate."
"The student was upset by the stupid mistakes in his work, often associated with inattention and not ignorance." A comma is placed before the sacrament.
As you can see from the above examples, the word "often" does not affect the punctuation.